class Move{
    timer = '';
     constructor(){
         
         this.scroll();
     }
   
     // 自动旋转
     scroll(){
         let pos = 0;
         this.timer = setInterval(() => {
             pos--;
             if(pos <= -400){
                 pos = 0;
             }
             this.$('.bb ul').style.left = pos + 'px';
         },30)
     } 
     $(ele){
         let res = document.querySelectorAll(ele);
         return res.length ==1 ? res[0] : res;
     }
 }
 new Move;